Update V8 postmortem metadata script

This commit updates the gen-postmortem-metadaa.py script to
incorporate changes in V8 8.5. This removes the need to float a
patch to the script in Node.js.

Change-Id: I6532495bee906f51eb2b773ec38ff0a6e404dafe
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2582705Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/master@{#71699}

tools/gen-postmortem-metadata.py

@@ -273,6 +273,8 @@ extras_accessors = [
     'UncompiledData, inferred_name, String, kInferredNameOffset',
     'UncompiledData, start_position, int32_t, kStartPositionOffset',
     'UncompiledData, end_position, int32_t, kEndPositionOffset',
+    'Script, name, Object, kNameOffset',
+    'Script, line_ends, Object, kLineEndsOffset',
     'SharedFunctionInfo, raw_function_token_offset, int16_t, kFunctionTokenOffsetOffset',
     'SharedFunctionInfo, internal_formal_parameter_count, uint16_t, kFormalParameterCountOffset',
     'SharedFunctionInfo, flags, int, kFlagsOffset',